Quickly skimmed through it.

Surely, near-instant money transfers with zero transaction fees is a key service. "Free payments" doesn't cut it in the Introduction.

SBD has always been Steem Backed Dollars.

Good to see mention of Optane. I've been hyping it up in the witness channel for the last few weeks.

A lot of details are not mentioned, hope to see these in future versions of the Whitepaper. I also expect to see the Whitepaper updated at each hardfork.